Scanning Field Emission Microscopy with Polarization Analysis (SFEMPA)

Bertolini, Gabriele; Pietro, L. De; Bähler, Thomas; Cabrera, H.; Gürlü, O.; Pescia, D.; Ramsperger, U.

doi:10.1016/j.elspec.2019.05.014

Cited by 5 publications

(10 citation statements)

References 30 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In recent experiments it was found that excited electrons in SEM could escape from the tip-target junction, helping in building new electronic systems based on polarized spin at nanoscale. Bertolini and co-authors [148] reported for the first time the scanning field emission microscopy with polarization analysis (SFEMPA). In SFEMPA a STM tip is held on one side and the spin polarization generated by electron scattering, thus providing the entire magnetic detail.…”

Section: Scanning Electron Microscopy With Polarization Analysis (Sempa)mentioning

confidence: 99%

Magnetic Materials and Systems: Domain Structure Visualization and Other Characterization Techniques for the Application in the Materials Science and Biomedicine

2020

View full text Add to dashboard Cite

Magnetic structures have attracted a great interest due to their multiple applications, from physics to biomedicine. Several techniques are currently employed to investigate magnetic characteristics and other physicochemical properties of magnetic structures. The major objective of this review is to summarize the current knowledge on the usage, advances, advantages, and disadvantages of a large number of techniques that are currently available to characterize magnetic systems. The present review, aiming at helping in the choice of the most suitable method as appropriate, is divided into three sections dedicated to characterization techniques. Firstly, the magnetism and magnetization (hysteresis) techniques are introduced. Secondly, the visualization methods of the domain structures by means of different probes are illustrated. Lastly, the characterization of magnetic nanosystems in view of possible biomedical applications is discussed, including the exploitation of magnetism in imaging for cell tracking/visualization of pathological alterations in living systems (mainly by magnetic resonance imaging, MRI).

show abstract

Section: Scanning Electron Microscopy With Polarization Analysis (Sempa)mentioning

confidence: 99%

Magnetic Materials and Systems: Domain Structure Visualization and Other Characterization Techniques for the Application in the Materials Science and Biomedicine

2020

View full text Add to dashboard Cite

show abstract

“…25,26 Q is a parameter taking into account instrumental asymmetries 25 not related to Pñ : it is determined by averaging online the counting rates over a region of the target with vanishing magnetization (e.g., the Wsurface). 24 Our instrument is able to detect simultaneously two components of the spin polarization vector: P x along the x-direction (Fig. 1), corresponding to one in-plane component of the target magnetization vector, and the component P z along the z-direction, corresponding to the component of the magnetization vector perpendicular to the target plane.…”

mentioning

confidence: 99%

“…21 The technology was called with an acronym that describes its dual origin: SFEMPA, standing for Scanning Field Emission with Polarization Analysis. 24 Preliminary experiments (using some image processing) detected the magnetization of uniformly magnetized thin elements. The imaging with SFEMPA of a nonuniformly magnetized thin film with juxtaposed domains of opposite magnetization vector, based on raw experimental data, was not achieved yet.…”

mentioning

confidence: 99%

“…efficient, nonmagnetic field-emitters based on W are given elsewhere. 24 All experiments presented here are performed in ultrahigh-vacuum conditions with a base pressure in the low 10 À11 mbar range and at room temperature. The Fe films on W(110) are grown at room temperature (for further details, see Ref.…”

mentioning

confidence: 99%

“…The Fe films on W(110) are grown at room temperature (for further details, see Ref. 24). The polycrystalline Fe crystal is mechanically polished to optical flatness and then prepared in ultrahighvacuum conditions with repeated sequences of Ar-sputtering and annealing to about 740 C. The Co-films on Pt(111) are deposited by molecular beam epitaxy.…”

mentioning

confidence: 99%

See 2 more Smart Citations

Vectorial, non-destructive magnetic imaging with scanning tunneling microscopy in the field emission regime

Ramsperger

Pescia

2019

Applied Physics Letters

Self Cite

View full text Add to dashboard Cite

When a scanning tunneling microscope is operated at tip-target distances ranging from few nanometers to few tens of nanometers (Fowler-Nordheim or field emission regime), a new electronic system appears, consisting of electrons that escape the tip-target junction. If the target is ferromagnetic, this electronic system is spin polarized. Here, we use these spin polarized electrons to image magnetic domains in thin films. As two components of the spin polarization vector are detected simultaneously, the imaging of the local magnetization has vectorial character. The tip is nonmagnetic, i.e., the magnetic state of the target is not perturbed by the act of probing. We expect this spin polarized technology, which scales down scanning electron microscopy with polarization analysis by bringing the source of primary electrons in close proximity to the target, to find its main applications in the imaging of noncollinear, weakly stable spin excitations.

show abstract

Scanning tunneling microscopy in the field-emission regime: Formation of a two-dimensional electron cascade

Werner

Oral

Radlička

et al. 2019

Applied Physics Letters

Self Cite

View full text Add to dashboard Cite

The signal generation mechanism of the scanning field-emission microscope has been investigated via model calculations combining deterministic trajectory calculations in the field surrounding the field-emission tip in vacuum, with Monte Carlo simulations of the electron transport inside the solid. This model gives rise to a two-dimensional electron cascade. Individual trajectories of detected backscattered electrons consist of repeated segments of travel in vacuum followed by a re-entry into the solid and re-emission into vacuum after being elastically or inelastically scattered. These so-called electron bouncing events also create secondary electrons at macroscopic distances away from the primary impact position. The signal reaching the detector is made up of elastically and inelastically backscattered primary electrons created near the impact position under the tip and those secondary electrons created far away from it.

show abstract

Scanning Field Emission Microscopy with Polarization Analysis (SFEMPA)

Cited by 5 publications

References 30 publications

Magnetic Materials and Systems: Domain Structure Visualization and Other Characterization Techniques for the Application in the Materials Science and Biomedicine

Magnetic Materials and Systems: Domain Structure Visualization and Other Characterization Techniques for the Application in the Materials Science and Biomedicine

Vectorial, non-destructive magnetic imaging with scanning tunneling microscopy in the field emission regime

Scanning tunneling microscopy in the field-emission regime: Formation of a two-dimensional electron cascade

Contact Info

Product

Resources

About